Compositions and processes for photolithography

ABSTRACT

New photoresist compositions are provided that are useful for immersion lithography. In one preferred aspect, photoresist composition are provided that comprise: (i) one or more resins that comprise photoacid-labile groups, (ii) a photoactive component, and (iii) one or more materials that comprise photoacid labile groups and that are distinct from the one or more resins; wherein the deprotection activation energy of photoacid-labile groups of the one or more materials is about the same as or lower than the deprotection activation energy of photoacid-labile groups of the one or more resins. In another preferred aspect, photoresist compositions are provided that comprise (i) one or more resins, (ii) a photoactive component, and (iii) one or more materials that comprise a sufficient amount of acidic groups to provide a dark field dissolution rate of at least one angstrom per second.

The present invention relates to new photoresist compositions that areparticularly useful in immersion lithography processes. In one aspect,preferred photoresist compositions of the invention will have aspecified developer dissolution rate. In another aspect, preferredphotoresist compositions will have multiple, distinct resins withdistinct photoacid-labile groups.

Photoresists are photosensitive films used for transfer of an image to asubstrate. A coating layer of a photoresist is formed on a substrate andthe photoresist layer is then exposed through a photomask to a source ofactivating radiation. The photomask has areas that are opaque toactivating radiation and other areas that are transparent to activatingradiation. Exposure to activating radiation provides a photoinducedchemical transformation of the photoresist coating to thereby transferthe pattern of the photomask to the photoresist coated substrate.Following exposure, the photoresist is developed to provide a reliefimage that permits selective processing of a substrate. See U.S. PatentApplication Publication 2006/0246373.

The growth of the semiconductor industry is driven by Moore's law whichstates that the complexity of an IC device doubles on average every twoyears. This necessitates the need to lithographically transfer patternsand structures with ever decreasing feature size.

While currently available photoresists are suitable for manyapplications, current resists also can exhibit significant shortcomings,particularly in high performance applications such as formation ofhighly resolved sub-quarter micron and even sub-tenth micron features.

We now provide new photoresist compositions and processes.

More particularly, in one aspect, preferred photoresists may comprise

-   -   (i) one or more resins that comprise photoacid-labile groups,    -   (ii) a photoactive component, and    -   (iii) one or more materials that comprise photoacid labile        groups and that are distinct from the one or more resins;

wherein the deprotection activation energy of photoacid-labile groups ofthe one or more materials is about the same as or lower than thedeprotection activation energy of photoacid-labile groups of the one ormore resins. Preferably, the one or more materials are substantiallynon-mixable with the one or more resins.

In this aspect, also preferred is where the deprotection activationenergy of photoacid-labile groups of the one or more materials is lowerthan the deprotection activation energy of photoacid-labile groups ofthe one or more resins. For example, the photoacid-labile groups of theone or more materials react (particularly deprotect to provide a moreacidic group such as —COOH) at a lower temperature (e.g. at least 5, 10,15, 20, 25, 30, 35, 40, 45 or 50 degrees centigrade or lower) than thetemperature where the photoacid-labile groups of the one or more resinsreact (particularly deprotect to provide a more acidic group such as—COOH). Such differences in reactivity may occur during a post-exposurebake step of the photoresist layer during lithographic processing.

For example, in one embodiment, the one or more resins may compriseester photoacid-labile groups (e.g. as may be provided by polymerizationby t-butyl acrylate) and the one or more materials may comprise acetalphotoacid-labile groups.

In another embodiment, both the one or more resins and the one or morematerials may each comprise ester photoacid-labile groups, but the oneor more materials will comprise more highly branced ester groups such asmore highly branched carbon chains (e.g. photoacid-labile groups of theformula —C(═O)OR where R is a more highly branched ester groups of theone or more materials relative to the one or more resins).

In another aspect, photoresists are provided comprising

-   -   (i) one or more resins,    -   (ii) a photoactive component, and    -   (iii) one or more materials that comprise a sufficient amount of        acidic groups to provide a dark field dissolution rate of at        least one angstrom per second.

In this aspect, suitable acidic groups of the one or more materialsinclude e.g. the one or more materials comprise one or more acidicgroups selected from fluorinated alcohols (e.g. (CF₃)₂((OH)—),sulfonamide, hetero-substituted carbocyclic aryl (e.g. hydronaphthyl),and carboxy (e.g. —COOH). Preferably, the one or more materials thatcomprise a sufficient amount of acidic groups to provide a dark fielddissolution rate of at least two, three, four or five angstroms persecond. The amount of acidic groups in a particular material (e.g.resin) to provide a desired developer dissolution rate can be determinedempirically. As referred to herein, a dark field developer rate of theone or more materials of a photoresist composition is determined asfollows: the one or more materials are formulated as a 3 percent byweight fluid composition in ethyl lactate. The ethyl lactate formulationis coated onto a silicon microelectronic wafer and solvent removed underoft-bake conditions (110° C. for 60 seconds) such as with a vacuumhotplate. The soft-baked layer is then treated (puddle) mode with 0.26 Ntetramethyl ammonium hydroxide developer and the layer thickness los ismeasured by standard procedures such as with a quartz crystalmicrobalance or dissolution rate monitor.

Particularly preferred photoresists of the invention can exhibit reduceddefects associated with a resist relief image formed from thephotoresist composition. In certain aspects, micro-bridging betweenlines of the formed resist relief image can be minimized or avoided.

In all aspects of the invention, preferably, the one or more materialsare substantially non-mixable with the one or more resins. As referredto herein, one or more materials that are substantially non-mixable withthe one or more photoresist resins can be any material added to aphotoresist that results in reduced defects upon aqeuous alkalinedevelopment.

Suitable substantially non-mixable materials for use in photoresists ofthe invention include compositions that comprise silicon and/or fluorinesubstitution.

Preferred one or more materials for use in of the invention compriseacidic groups such as carboxy, fluorinated alcohols (e.g. (CF₃)₂C(OH)—),sulfonamide, and/or hetero-substituted carbocyclic aryl moieties.

Also preferred are those substantially non-mixable materials thatcontain photoacid-labile groups, such as photoacid-labile ester oracetal groups, including such groups as described herein employed in aresin component of a chemically amplified photoresist.

Preferred substantially non-mixable materials for use in photoresists ofthe invention also will be soluble in the same organic solvent(s) usedto formulate the photoresist composition.

Particularly preferred substantially non-mixable materials for use inphotoresists of the invention also will have lower surface energy and/orsmaller hydrodynamic volume than the one or more resins of thephotoresist's resin component. The lower surface energy can facilitatesegregation or migration of the substantially non-mixable materials totop or upper portions of an applied the photoresist coating layer.Additionally, relative smaller higher hydrodynamic volume also can bepreferred because it can facilitate efficient migration (higherdiffusion coefficient) of the one or more substantially non-mixablematerials to upper regions of the applied photoresist coating layer.

Preferred substantially non-mixable materials for use in photoresists ofthe invention also will be soluble in photoresist developer compositions(e.g. 0.26N aqueous alkaline solution). Thus, in addition tophotoacid-labile groups as discussed above, other aqueousbase-solubilizing groups may be included in the substantiallynon-mixable materials such as hydroxyl, fluoroalcohol (e.g. —CH(CF₃)₂),carboxy and the like.

Suitable substantially non-mixable materials for use in photoresists ofthe invention also may be in the form of particles. Such particles mayinclude polymers that are polymerized in the form discrete particles,i.e. as separate and distinct polymer particles. Such polymer particlestypically have one or more different characteristics from linear orladder polymers such as linear or ladder silicon polymers. For example,such polymer particles may have a defined size and a low molecularweight distribution. More particularly, in a preferred aspect, aplurality of the polymer particles may be employed in a photoresist ofthe invention with a mean particle size (dimension) of from about 5 to3000 angstroms, more preferably from about 5 to 2000 angstroms, stillmore preferably from about 5 to about 1000 angstroms, yet morepreferably from about 10 to about 500 angstroms, even more preferablyfrom 10 to 50 or 200 angstroms. For many applications, particularlypreferred particles have a mean particle size of less than about 200 or100 angstroms.

Additional suitable substantially non-mixable materials for use inphotoresists of the invention may have Si content, includingsilsesquioxane materials, materials with SiO₂ groups, and the like.Preferred silicon-containing substantially non-mixable materials alsoinclude polyhedral oligomeric silsesquioxanxes.

Preferred materials include the following:

Branched photoacid-labile groups:

As discussed above, in certain aspects, photoacid-labile groups of theone or more materials may be more highly branched than thephotoacid-labile groups of the one or more resins. Suitable highlybranched photoacid-labile ester groups for use in the one or morematerials in this aspect are disclosed in U.S. Pat. No. 6,136,501. Forinstance, suitable branched photoacid-labile ester groups may comprisean optionally substituted alkyl moiety having about 5 or more carbonatoms, with at least two branched carbon atoms, i.e. at least twosecondary, tertiary or quaternary carbon atoms. The alkyl moiety can bea noncyclic or single ring alicyclic group. Suitable alkyl moietiesinclude those that have one, two or more tertiary carbon atoms, and/orone, two or more quaternary carbons. References herein to a “secondary”carbon indicate the carbon atom has two non-hydrogen substituents (i.e.CH₂ RR¹ where R and R¹ are the same or different and each is other thanhydrogen); references herein to a “tertiary” carbon indicate the carbonatom has three non-hydrogen substituents (i.e. CHRR¹ R² where R, R¹ andR² are the same or different and each is other than hydrogen); andreferences herein to a “quaternary” carbon indicate the carbon atom hasfour non-hydrogen substituents (i.e. CRR¹ R², R³ where R, R¹, R² and R³are each the same or different and each is other than hydrogen). See,for instance, Morrison and Boyd, Organic Chemistry, particularly at page85 (3^(rd) ed., Allyn and Bacon), for a discussion of those termssecondary, tertiary and quaternary. It also should be understood thatreferences herein to “alkyl” are inclusive of linked or branched carbonchains such as alkylidene, alkylene and the like. Additionally, forpurposes of the present disclosure, the keto carbon (i.e. C═O) of theester linkage is referred to herein as the “carbonyl oxygen”, and thelinked oxygen (i.e. C═O(O)) is referred to herein as the “carboxyloxygen”. It is often preferred that a quaternary carbon is directlylinked (i.e. covalently linked with no other interposed atoms) to theester carboxyl oxygen, as is depicted in the above structure.

Acidic Groups:

As discussed above, preferred one or more materials for use in of theinvention comprise acidic groups such as carboxy, fluorinated alcohols(e.g. (CF₃)₂C(OH)—), sulfonamide, and/or hetero-substituted carbocyclicaryl moieties. Those acidic groups are further discussed as follows.

Carboxy Groups

Such groups include moieties with functionalities of —COOH, such asC₁₋₂₅alkyl substituted with one or more —COOH groups.

Sulfonamide Groups

Preferred photoresist compositions may comprise one or more materialthat comprise optionally substituted sulfonamide groups, includinggroups such as RS(═O)(X)NR′₂ where R is a non-hydrogen substituent,particularly —OH (to provide —SO₃H), optionally substituted C₁₋₂₀alkyl,and an electron-withdrawing group such as halogen especially fluoro orhaloalkyl such as fluoralkyl e.g. F₃C—. In the formula RS(═O)(X)NR′₂, Xis a spacer (e.g. a chemical bond or a 1 to 8 carbon linkage), and eachR′ is independently a hydrogen or non-hydrogen substituent such asoptionally substituted C₁₋₂₀alkyl including a group as defined for Rabove.

It thus should be understood that references herein to “sulfonamide” areinclusive of where a sulfono (SO₂) moiety is directly linked (e.g. X informula RS(═O)(X)NR′₂ is chemical bond) to nitrogen as well as where asulfono (SO₂) moiety is spaced by 1, 2, 3 or more atoms (such as carbonatoms, e.g. X in formula RS(═O)(X)NR′₂ is (—CH₂—)₁₋₃) from the nitrogenof the sulfonamide group.

In certain aspects of the invention, preferred are photoresistcompositions that comprise materials that: comprise sulfonamide group(s)where a sulfono (SO₂) moiety is spaced by 1, 2, 3 or more non-nitrogenatoms from the most adjacent nitrogen of the sulfonamide moiety.

Hetero-Substituted Carbocyclic Aryl

Preferred substituted carbocyclic aryl units for incorporation into aresin are naphthyl groups as well as other substituted carbocyclic arylmoieties such as hetero-substituted phenyl, anthracenyl, acenaphthyl,phenanthryl, and the like. Generally, hetero-substituted carbocyclicaryl groups having multiple fused rings (e.g. 2 or 3 fused rings, atleast one of which is a carbocyclic aryl) are preferred such ashetero-substituted naphthyl, anthracenyl, acenaphthyl, phenanthryl, andthe like.

A carbocyclic group may have a variety of hetero-substituents, withoxygen- and sulfur-containing substituents being generally preferred.For instance, preferred hetero-substituted carbocyclic aryl groups ofresins of the invention include those aryl groups having one or morehydroxy (—OH), thio (—SH), alcohol (e.g. hydroxyC₁₋₆alkyl), thioalkyl(e.g. HSC₁₋₆alkyl), alkanoyl (e.g. C₁₋₆alkanoyl such as formyl or acyl),alkylsulfide such as C₁₋₆alkylsulfide, carboxylate (includingC₁₋₁₂ester), alkyl ether including C₁₋₈ether, and the like. Preferably,at least one hetero atom of the hetero-containing substituent has ahydrogen substituent (e.g. hydroxy is preferred over alkoxy).

It is also preferred that the hetero group has the hetero atom directlylinked to the carbocyclic ring (such as a hydroxy or thio ringsubstituents), or a hetero atom is a substituent of an activated carbonsuch as a ring substituent of —CH₂OH or —CH₂SH, or other primary hydroxyor thio alkyl.

Preferred materials having hetero-substituted carbocyclic aryl units(which can be substantially non-mixable materials) for use inphotoresists of the invention also may comprise repeat units in additionto substituted carbocyclic aryl units, particularly non-aromatic unitssuch as provided by polymerization of an acrylate or an optionallysubstituted cyclic olefin (particularly carbon alicyclic orheteroalicyclic group) such as a polymerized optionally substitutednorbornene. Preferably, at least one of the resin repeat units containsa photoacid-labile moiety such as a photoacid-labile ester or acetalmoiety. For use in a photoresist imaged at 193 nm, particularlypreferred substantially non-mixable resins are substantially free of anyaromatic moieties other than the hydroxy naphthyl groups or otherhetero-substituted carbocyclic aryl groups.

Additional preferred polymer units may be provided by polymerization ofan anhydride such as maleic anhydride or itaconic anhydride; or lactonessuch as provided by polymerization of a suitable acrylate e.g.acryloxy-norbornane-butyrolactone and the like.

A material having hetero-substituted carbocyclic aryl units (which canbe substantially non-mixable materials) for use in photoresists of theinvention may suitably contain a relatively wide range of amounts ofhydroxy naphthyl units or other hetero-substituted carbocyclic arylgroups. Good lithographic results can be realized with use of a resinthat contains quite minor amounts of the hydroxy naphthyl units. Forexample, a resin (which can be a substantially non-mixable material) foruse in photoresists of the invention may suitably contain less thanabout 50 or 40 mole percent of hetero-substituted carbocyclic aryl unitsbased on total units of a resin, or even less than about 30, 20, 15 or10 mole percent of hetero-substituted carbocyclic aryl units based ontotal units of the polymer. Indeed, a substantially non-mixable resinmay suitably contain about 0.5, 1, 2, 3, 4, 5, 6, 7 or 8 mole percent ofhydroxy naphthyl units based on total units of the resin. Typically, aresin will contain at least about 1, 2, 3, 4 or 5 mole percent ofhetero-substituted carbocyclic aryl units such as hydroxy naphthyl unitsbased on total resin units. Generally preferred are resins that containat least or up to about 5, 10, 20, 30, 40, or 45 hetero-substitutedcarbocyclic aryl units such as hydroxy naphthyl units based on totalresin units.

Preferred materials having hetero-substituted carbocyclic aryl units(which can be substantially non-mixable materials) for use inphotoresists of the invention imaged at 193 nm and suitably will besubstantially free of any phenyl or other aromatic groups other than thehetero-substituted carbocyclic aryl units. For example, preferredpolymers contain less than about 5 mole percent aromatic groups otherthan the hetero-substituted carbocyclic aryl units, more preferably lessthan about 1 or 2 mole percent aromatic groups hetero-substitutedcarbocyclic aryl units.

As discussed, various moieties of hetero-substitutred carbocylic arylmaterials, resin units and other components of photoresists of theinvention may be optionally substituted. A “substituted” substituent maybe substituted at one or more available positions, typically 1, 2, or 3positions by one or more suitable groups such as e.g. halogen(particularly F, Cl or Br); cyano; C₁₋₈ alkyl; C₁₋₈ alkoxy; C₁₋₈alkylthio; C₁₋₈ alkylsulfonyl; C₂₋₈ alkenyl; C₂₋₈ alkynyl; hydroxyl;nitro; alkanoyl such as a C₁₋₆ alkanoyl e.g. acyl and the like; etc.

Preferred substituted carbocyclic aryl units for incorporation into aresin are naphthyl groups substituted with one or more hydroxy (—OH),thio (—SH), alcohol (e.g. hydroxyC₁₋₆alkyl), thioalkyl (e.g.HSC₁₋₆alkyl), alkanoyl (e.g. C₁₋₆alkanoyl such as formyl or acyl),alkylsulfide such as C₁₋₆alkylsulfide, carboxylate (includingC₁₋₁₂ester), alkyl ether including C₁₋₈ether, and the like. Preferably,at least one hetero atom of the hetero-containing substituent has ahydrogen substituent (e.g. hydroxy is preferred over alkoxy). It is alsopreferred that the hetero group has the hetero atom directly linked tothe carbocyclic ring (such as a hydroxy or thio ring substituents), or ahetero atom is a substituent of an activated carbon such as a ringsubstituent of —CH₂OH or —CH₂SH, or other primary hydroxy or thio alkyl.

Fluorinated Alcohols

A wide range of fluorinated alcohol groups may be employed includingC1-25alkyl substituted with one or more fluorine atoms. A particularlypreferred fluoroalcohol group is (CF₃)₂C(OH)—.

Preferred imaging wavelengths of lithographic systems of the inventioninclude sub-300 nm wavelengths e.g. 248 nm, and sub-200 nm wavelengthse.g. 193 nm. In addition to one or more substantially non-mixablematerials, particularly preferred photoresists of the invention maycontain a photoactive component (e.g. one or more photoacid generatorcompounds) and one or more resins that are chosen from among:

-   -   1) a phenolic resin that contains acid-labile groups that can        provide a chemically amplified positive resist particularly        suitable for imaging at 248 nm. Particularly preferred resins of        this class include: i) polymers that contain polymerized units        of a vinyl phenol and an alkyl acrylate, where the polymerized        alkyl acrylate units can undergo a deblocking reaction in the        presence of photoacid. Exemplary alkyl acrylates that can        undergo a photoacid-induced deblocking reaction include e.g.        t-butyl acrylate, t-butyl methacrylate, methyladamantyl        acrylate, methyl adamantyl methacrylate, and other non-cyclic        alkyl and alicyclic acrylates that can undergo a        photoacid-induced reaction, such as polymers in U.S. Pat. Nos.        6,042,997 and 5,492,793, incorporated herein by reference; ii)        polymers that contain polymerized units of a vinyl phenol, an        optionally substituted vinyl phenyl (e.g. styrene) that does not        contain a hydroxy or carboxy ring substituent, and an alkyl        acrylate such as those deblocking groups described with        polymers i) above, such as polymers described in U.S. Pat. No.        6,042,997, incorporated herein by reference; and iii) polymers        that contain repeat units that comprise an acetal or ketal        moiety that will react with photoacid, and optionally aromatic        repeat units such as phenyl or phenolic groups; such polymers        have been described in U.S. Pat. Nos. 5,929,176 and 6,090,526,        incorporated herein by reference, as well as blends of i)        and/or ii) and/or iii);    -   2) phenolic resins that do not contain acid-labile groups such        as poly(vinylphenol) and novolak resins that may be employed in        I-line and G-line photoresists together with a        diazonaphthoquinone photoactive compound and have been described        e.g. in U.S. Pat. Nos. 4,983,492; 5,130,410; 5,216,111; and        5,529,880;    -   3) a resin that is substantially or completely free of phenyl or        other aromatic groups that can provide a chemically amplified        positive resist particularly suitable for imaging at sub-200 nm        wavelengths such as 193 nm. Particularly preferred resins of        this class include: i) polymers that contain polymerized units        of a non-aromatic cyclic olefin (endocyclic double bond) such as        an optionally substituted norbornene, such as polymers described        in U.S. Pat. Nos. 5,843,624, and 6,048,664, incorporated herein        by reference; ii) polymers that contain alkyl acrylate units        such as e.g. t-butyl acrylate, t-butyl methacrylate,        methyladamantyl acrylate, methyl adamantyl methacrylate, and        other non-cyclic alkyl and alicyclic acrylates; such polymers        have been described in U.S. Pat. No. 6,057,083; European        Published Applications EP01008913A1 and EP00930542A1; and U.S.        pending patent application Ser. No. 09/143,462, all incorporated        herein by reference, and iii) polymers that contain polymerized        anhydride units, particularly polymerized maleic anhydride        and/or itaconic anhydride units, such as disclosed in European        Published Application EP01008913A1 and U.S. Pat. No. 6,048,662,        both incorporated herein by reference, as well as blends of i)        and/or ii) and/or iii);    -   4) a resin that contains repeat units that contain a hetero        atom, particularly oxygen and/or sulfur (but other than an        anhydride, i.e. the unit does not contain a keto ring atom), and        preferable are substantially or completely free of any aromatic        units. Preferably, the heteroalicyclic unit is fused to the        resin backbone, and further preferred is where the resin        comprises a fused carbon alicyclic unit such as provided by        polymerization of a norborene group and/or an anhydride unit        such as provided by polymerization of a maleic anhydride or        itaconic anhydride. Such resins are disclosed in PCT/US01/14914        and U.S. application Ser. No. 09/567,634.    -   5) resins that contain Si-substitution including        poly(silsequioxanes) and the like and may be used with an        undercoated layer. Such resins are disclosed e.g. in U.S. Pat.        No. 6,803,171.    -   6) a resin that contains fluorine substitution (fluoropolymer),        e.g. as may be provided by polymerization of        tetrafluoroethylene, a fluorinated aromatic group such as        fluoro-styrene compound, compounds that comprise a        hexafluoroalcohol moiety, and the like. Examples of such resins        are disclosed e.g. in PCT/US99/21912.

Preferred photoresists of the invention include bothchemically-amplified positive-acting and negative-acting photoresists.Typically preferred chemically-amplified positive resists include one ormore resins that comprise photoacid-labile groups such asphotoacid-labile ester or acetal groups.

The invention further provides methods for forming a photoresist reliefimage and producing an electronic device using photoresists of theinvention. The invention also provides novel articles of manufacturecomprising substrates coated with a photoresist composition of theinvention.

Other aspects of the invention are disclosed infra.

As discussed above, particularly preferred photoresists of the inventioncan exhibit reduced defects following aqueous alkaline development. Suchdefects can include reduced organic residues in areas bared ofphotoresist upon development as well as reduced microbridging betweenimages resist lines or other features.

As discussed above, suitable materials of photoresists of the inventionthat are substantially non-mixable with the resist resin component canbe readily identified by simple testing. In particular, as referred toherein, preferred substantially non-mixable materials will provide adecreased occurrence or amount of defects upon aqueous alkalinedevelopment relative to a comparable photoresist relative to the samephotoresist system that is processed into the same manner, but in theabsence of the candidate substantially non-mixable material(s).Assessment of defects (or absence thereof) can be made via scanningelectron micrography. Detection of photoresist material in the immersionfluid can be conducted as described in Example 2 of U.S. PatentPublication 2006/0246373 and includes mass spectroscopy analysis of theimmersion fluid before and after exposure to the photoresist. In suchanalysis, the immersion fluid directly contacts the tested photoresistcomposition layer for about 60 seconds during exposure. Preferably,addition of one or more substantially non-mixable materials provides atleast a 10 percent reduction in photoresist material (again, acid ororganics as detected by mass spectroscopy) residing in the immersionfluid relative to the same photoresist that does not employ suchsubstantially non-mixable material(s), more preferably the one or moresubstantially non-mixable materials provides at least a 20, 50, or 100,200, 500, or 1000 percent reduction photoresist material (again, acidand/or organics) residing in to the immersion fluid relative to the samephotoresist that does not contain the substantially non-mixablematerial(s).

Preferred photoresists of the invention will result in less than1.6×E-10 (mole/cm²/sec) of photoacid generator material being leachedinto deionized water or other overcoating immersion fluid for 60 secondsduring exposure by the analysis method described in Example 2 of U.S.Patent Publication 2006/0246373.

Preferred photoresists of the invention may have preferred water contactangles. As referred to herein, water contact angles, such as static,receding, advancing sliding, developer static can be determined inaccordance with the producers disclosed in Burnett et al., J. Vac. Sci.Techn. B, 23(6), pages 2721-2727 (November/December 2005). Preferredphotoresists (as determined as a spin-coated layer with solvent removedby soft-bake) will have a receding angle of at least 65°, morepreferably at least 70°. Additionally, preferred substantiallynon-mixable materials (as determined as a spin-coated layer with solventremoved by soft-bake) will have a receding angle of at least 65°, morepreferably at least 70°.

Particularly preferred materials (which may be substantially non-mixablewith the one or more polymers) include higher order polymers e.g.copolymers, terpolymers, tetrapolymers and pentapolymers. Particularlypreferred are such polymers that comprise fluorine substitution.Preferred fluoro substitution include perfluoro groups e.g. F₃C—,F₃CCF₂—, and fluorinated alcohols e.g. (F₃C)₂C(OH)—. Preferred resin oneor more materials may have a wide range of molecular weights includingMw of from 1,000 to 100,000, more typically about 1,000 to about 20,000or 30,000.

Specifically preferred substantially non-mixable resins for use inphotoresists of the invention include the following. Alos, the branchedester group moieties depicted below (i.e. —C(CH₂CH₃)(CH₃)₂—C(CH₂CH₃)₃,—C(CH(CH₃)₂)₃, —C(CH₃)₂CH(CH₃)₂, etc.) are particularly preferredbranched groups

where R1 through R3 in each of the above structures in hydrogen ormethyl

Additional specifically preferred substantially non-mixable resins foruse in photoresists of the invention include the following (q with thebelow group —(ethyl)cyclopentyl being another particularly preferredbranched group):

As discussed above, suitable substantially non-mixable materials includeSi-containing materials. Especially preferred substantially non-mixablematerials include nanostructured compositions, which are commerciallyavailable from groups such as Hybrid Plastics (Fountain Valley, Calif.),Sigma/Aldrich, and others. Such materials may include molecular silicaswhich have a Si—O core enveloped by organic groups; silanols; andpolymers and resins which include silsesquioxane cage-structuredcompounds and may be silicones, styrenics, acrylics, alicyclics such asnorbornenes and others.

Particles (including organic particles) useful as substantiallynon-mixable materials include Si-containing and fluorinated materialsthat have carboxy substitution. Such particles are commerciallyavailable, or can be readily synthesized, e.g. by reaction of one ormore monomers together with a crosslinking agent and an initiatorcompound If desired. The reacted monomers may have substitution asdesired e.g. fluorine, Si groups, photoacid-labile groups such asphotoacid-labile esters or acetals, other base-solubilizing groups suchas alcohols and the like. See Example 1 which follows for an exemplarysynthesis of such particles produced with multiple distinct monomers,where one of the monomers provides a photoacid-labile group to theresulting polymer particle.

The substantially non-mixable material(s) may be present in aphotoresist composition in relatively small amounts and still provideeffective results. For instance, the one or more substantiallynon-mixable materials may be suitable present in about 0.1 to 20 weightpercent based on total weight of a fluid photoresist composition.Suitable amounts also are provided in the examples which follow.

As discussed above, preferred photoresists for use in accordance withthe invention include positive-acting or negative-acting chemicallyamplified photoresists, i.e. negative-acting resist compositions whichundergo a photoacid-promoted crosslinking reaction to render exposedregions of a coating layer of the resist less developer soluble thanunexposed regions, and positive-acting resist compositions which undergoa photoacid-promoted deprotection reaction of acid labile groups of oneor more composition components to render exposed regions of a coatinglayer of the resist more soluble in an aqueous developer than unexposedregions. Ester groups that contain a tertiary non-cyclic alkyl carbon(e.g. t-butyl) or a tertiary alicyclic carbon (e.g. methyladamantyl)covalently linked to the carboxyl oxygen of the ester are oftenpreferred photoacid-labile groups of resins employed in photoresists ofthe invention. Acetal photoacid-labile groups also will be preferred.

Preferred photoresists of the invention typically comprise a resincomponent and a photoactive component. Preferably the resin hasfunctional groups that impart alkaline aqueous developability to theresist composition. For example, preferred are resin binders thatcomprise polar functional groups such as hydroxyl or carboxylate.Preferably a resin component is used in a resist composition in anamount sufficient to render the resist developable with an aqueousalkaline solution.

For imaging at wavelengths greater than 200 nm, such as 248 nm, phenolicresins are typically preferred. Preferred phenolic resins are poly(vinylphenols) which may be formed by block polymerization, emulsionpolymerization or solution polymerization of the corresponding monomersin the presence of a catalyst. Vinylphenols useful for the production ofpolyvinyl phenol resins may be prepared, for example, by hydrolysis ofcommercially available coumarin or substituted coumarin, followed bydecarboxylation of the resulting hydroxy cinnamic acids. Usefulvinylphenols may also be prepared by dehydration of the correspondinghydroxy alkyl phenols or by decarboxylation of hydroxy cinnamic acidsresulting from the reaction of substituted or nonsubstitutedhydroxybenzaldehydes with malonic acid. Preferred polyvinylphenol resinsprepared from such vinylphenols have a molecular weight range of fromabout 2,000 to about 60,000 daltons.

Also preferred for imaging at wavelengths greater than 200 nm, such as248 nm are chemically amplified photoresists that comprise in admixturea photoactive component and a resin component that comprises a copolymercontaining both phenolic and non-phenolic units. For example, onepreferred group of such copolymers has acid labile groups substantially,essentially or completely only on non-phenolic units of the copolymer,particularly alkylacrylate photoacid-labile groups, i.e. aphenolic-alkyl acrylate copolymer. One especially preferred copolymerbinder has repeating units x and y of the following formula:

wherein the hydroxyl group be present at either the ortho, meta or parapositions throughout the copolymer, and R′ is substituted orunsubstituted alkyl having 1 to about 18 carbon atoms, more typically 1to about 6 to 8 carbon atoms. Tert-butyl is a generally preferred R′group. An R′ group may be optionally substituted by e.g. one or morehalogen (particularly F, Cl or Br), C₁₋₈ alkoxy, C₂₋₈ alkenyl, etc. Theunits x and y may be regularly alternating in the copolymer, or may berandomly interspersed through the polymer. Such copolymers can bereadily formed. For example, for resins of the above formula, vinylphenols and a substituted or unsubstituted alkyl acrylate such ast-butylacrylate and the like may be condensed under free radicalconditions as known in the art. The substituted ester moiety, i.e.R′—O—C(═O)—, moiety of the acrylate units serves as the acid labilegroups of the resin and will undergo photoacid induced cleavage uponexposure of a coating layer of a photoresist containing the resin.Preferably the copolymer will have a M_(W) of from about 8,000 to about50,000, more preferably about 15,000 to about 30,000 with a molecularweight distribution of about 3 or less, more preferably a molecularweight distribution of about 2 or less. Non-phenolic resins, e.g. acopolymer of an alkyl acrylate such as t-butylacrylate ort-butylmethacrylate and a vinyl alicyclic such as a vinyl norbornanyl orvinyl cyclohexanol compound, also may be used as a resin binder incompositions of the invention. Such copolymers also may be prepared bysuch free radical polymerization or other known procedures and suitablywill have a M_(w) of from about 8,000 to about 50,000, and a molecularweight distribution of about 3 or less.

Other preferred resins that have acid-labile deblocking groups for usein a positive-acting chemically-amplified photoresist of the inventionhave been disclosed in European Patent Application 0829766A2 of theShipley Company. (resins with acetal and ketal resins) and EuropeanPatent Application EP0783136A2 of the Shipley Company (terpolymers andother copolymers including units of 1) styrene; 2) hydroxystyrene; and3) acid labile groups, particularly alkyl acrylate acid labile groupssuch as t-butylacrylate or t-butylmethacrylate). In general, resinshaving a variety of acid labile groups will be suitable, such as acidsensitive esters, carbonates, ethers, imides, etc. The photoacid labilegroups will more typically be pendant from a polymer backbone, althoughresins that have acid labile groups that are integral to the polymerbackbone also may be employed.

As discussed above, for imaging at sub-200 nm wavelengths such as 193nm, preferably a photoresist is employed that contains one or morepolymers that are substantially, essentially or completely free ofphenyl or other aromatic groups. For example, for sub-200 nm imaging,preferred photoresist polymers contain less than about 5 mole percentaromatic groups, more preferably less than about 1 or 2 mole percentaromatic groups, more preferably less than about 0.1, 0.02, 0.04 and0.08 mole percent aromatic groups and still more preferably less thanabout 0.01 mole percent aromatic groups. Particularly preferred polymersare completely free of aromatic groups. Aromatic groups can be highlyabsorbing of sub-200 nm radiation and thus are undesirable for polymersused in photoresists imaged with such short wavelength radiation.

Suitable polymers that are substantially or completely free of aromaticgroups and may be formulated with a PAG of the invention to provide aphotoresist for sub-200 nm imaging are disclosed in European applicationEP930542A1 and U.S. Pat. Nos. 6,692,888 and 6,680,159, all of theShipley Company.

Suitable polymers that are substantially or completely free of aromaticgroups suitably contain acrylate units such as photoacid-labile acrylateunits as may be provided by polymerization of methyladamanatylacrylate,methyladamantylmethacrylate, ethylfenchylacrylate,ethylfenchylmethacrylate, and the like; fused non-aromatic alicyclicgroups such as may be provided by polymerization of a norbornenecompound or other alicyclic compound having an endocyclic carbon-carbondouble bond; an anhydride such as may be provided by polymerization ofmaleic anhydride and/or itaconic anhydride; and the like.

Preferred negative-acting compositions of the invention comprise one ormore materials (such as a crosslinker component e.g. an amine-basedmaterials such as a melamine resin) that will cure, crosslink or hardenupon exposure to acid, and a photoactive component of the invention.Particularly preferred negative acting compositions comprise a resinbinder such as a phenolic resin, a crosslinker component and aphotoactive component of the invention. Such compositions and the usethereof has been disclosed in European Patent Applications 0164248 and0232972 and in U.S. Pat. No. 5,128,232 to Thackeray et al. Preferredphenolic resins for use as the resin binder component include novolaksand poly(vinylphenol)s such as those discussed above. Preferredcrosslinkers include amine-based materials, including melamine,glycolurils, benzoguanamine-based materials and urea-based materials.Melamine-formaldehyde resins are generally most preferred. Suchcrosslinkers are commercially available, e.g. the melamine resins soldby American Cyanamid under the trade names Cymel 300, 301 and 303.Glycoluril resins are sold by American Cyanamid under trade names Cymel1170, 1171, 1172, urea-based resins are sold under the trade names ofBeetle 60, 65 and 80, and benzoguanamine resins are sold under the tradenames Cymel 1123 and 1125.

For imaging at sub-200 nm wavelengths such as 193 nm, preferrednegative-acting photoresists are disclosed in WO 03077029 to the ShipleyCompany.

Photoresists of the invention also may contain other materials. Forexample, other optional additives include actinic and contrast dyes,anti-striation agents, plasticizers, speed enhancers, sensitizers (e.g.for use of a PAG of the invention at longer wavelengths such as I-line(i.e. 365 nm) or G-line wavelengths), etc. Such optional additivestypically will be present in minor concentration in a photoresistcomposition except for fillers and dyes which may be present inrelatively large concentrations such as, e.g., in amounts of from 5 to30 percent by weight of the total weight of a resist's dry components.

A preferred optional additive of resists of the invention is an addedbase, e.g. a caprolactam, which can enhance resolution of a developedresist relief image. The added base is suitably used in relatively smallamounts, e.g. about 1 to 10 percent by weight relative to the PAG, moretypically 1 to about 5 weight percent. Other suitable basic additivesinclude ammonium sulfonate salts such as piperidinium p-toluenesulfonateand dicyclohexylammonium p-toluenesulfonate; alkyl amines such astripropylamine and dodecylamine; aryl amines such as diphenylamine,triphenylamine, aminophenol,2-(4-aminophenyl)-2-(4-hydroxyphenyl)propane, etc.

The resin component of resists of the invention is typically used in anamount sufficient to render an exposed coating layer of the resistdevelopable such as with an aqueous alkaline solution. Moreparticularly, a resin binder will suitably comprise 50 to about 90weight percent of total solids of the resist. The photoactive componentshould be present in an amount sufficient to enable generation of alatent image in a coating layer of the resist. More specifically, thephotoactive component will suitably be present in an amount of fromabout 1 to 40 weight percent of total solids of a resist. Typically,lesser amounts of the photoactive component will be suitable forchemically amplified resists.

The resist compositions of the invention also comprise a photoacidgenerator (i.e. “PAG”) that is suitably employed in an amount sufficientto generate a latent image in a coating layer of the resist uponexposure to activating radiation. Preferred PAGs for imaging at 193 nmand 248 nm imaging include imidosulfonates such as compounds of thefollowing formula:

wherein R is camphor, adamantane, alkyl (e.g. C₁₋₁₂ alkyl) andperfluoroalkyl such as perfluoro(C₁₋₁₂alkyl), particularlyperfluorooctanesulfonate, perfluorononanesulfonate and the like. Aspecifically preferred PAG isN-[(perfluorooctanesulfonyl)oxy]-5-norbornene-2,3-dicarboximide.

Sulfonate compounds are also suitable PAGs, particularly sulfonatesalts. Two suitable agents for 193 nm and 248 nm imaging are thefollowing PAGS 1 and 2:

Such sulfonate compounds can be prepared as disclosed in European PatentApplication 96118111.2 (publication number 0783136), which details thesynthesis of above PAG 1.

Also suitable are the above two iodonium compounds complexed with anionsother than the above-depicted camphorsulfonate groups. In particular,preferred anions include those of the formula RSO₃— where R isadamantane, alkyl (e.g. C₁₋₁₂ alkyl) and perfluoroalkyl such asperfluoro (C₁₋₁₂alkyl), particularly perfluorooctanesulfonate,perfluorobutanesulfonate and the like.

Other known PAGS also may be employed in photoresists used in accordancewith the invention. Particularly for 193 nm imaging, generally preferredare PAGS that do not contain aromatic groups, such as theabove-mentioned imidosulfonates, in order to provide enhancedtransparency.

Photoresists of the invention also may contain other optional materials.For example, other optional additives include anti-striation agents,plasticizers, speed enhancers, etc. Such optional additives typicallywill be present in minor concentrations in a photoresist compositionexcept for fillers and dyes which may be present in relatively largeconcentrations, e.g., in amounts of from about 5 to 30 percent by weightof the total weight of a resist's dry components.

The photoresists used in accordance with the invention are generallyprepared following known procedures. For example, a resist of theinvention can be prepared as a coating composition by dissolving thecomponents of the photoresist in a suitable solvent such as, e.g., aglycol ether such as 2-methoxyethyl ether (diglyme), ethylene glycolmonomethyl ether, propylene glycol monomethyl ether; propylene glycolmonomethyl ether acetate; lactates such as ethyl lactate or methyllactate, with ethyl lactate being preferred; propionates, particularlymethyl propionate, ethyl propionate and ethyl ethoxy propionate; aCellosolve ester such as methyl Cellosolve acetate; an aromatichydrocarbon such toluene or xylene; or a ketone such as methylethylketone, cyclohexanone and 2-heptanone. Typically the solids content ofthe photoresist varies between 5 and 35 percent by weight of the totalweight of the photoresist composition. Blends of such solvents also aresuitable.

Liquid photoresist compositions may be applied to a substrate such as byspinning, dipping, roller coating or other conventional coatingtechnique. When spin coating, the solids content of the coating solutioncan be adjusted to provide a desired film thickness based upon thespecific spinning equipment utilized, the viscosity of the solution, thespeed of the spinner and the amount of time allowed for spinning.

Photoresist compositions used in accordance with the invention aresuitably applied to substrates conventionally used in processesinvolving coating with photoresists. For example, the composition may beapplied over silicon wafers or silicon wafers coated with silicondioxide for the production of microprocessors and other integratedcircuit components. Aluminum-aluminum oxide, gallium arsenide, ceramic,quartz, copper, glass substrates and the like are also suitablyemployed. Photoresists also may be suitably applied over anantireflective layer, particularly an organic antireflective layer.

Following coating of the photoresist onto a surface, it may be dried byheating to remove the solvent until preferably the photoresist coatingis tack free. The photoresist layer (with overcoated barrier compositionlayer, if present) in then exposed in an immersion lithography system,i.e. where the space between the exposure tool (particularly theprojection lens) and the photoresist coated substrate is occupied by animmersion fluid, such as water or water mixed with one or more additivessuch as cesium sulfate which can provide a fluid of enhanced refractiveindex. Preferably the immersion fluid (e.g., water) has been treated toavoid bubbles, e.g. water can be degassed to avoid nanobubbles.

References herein to “immersion exposing” or other similar termindicates that exposure is conducted with such a fluid layer (e.g. wateror water with additives) interposed between an exposure tool and thecoated photoresist composition layer.

The photoresist composition layer is then suitably patterned exposed toactivating radiation with the exposure energy typically ranging fromabout 1 to 100 mJ/cm², dependent upon the exposure tool and thecomponents of the photoresist composition. References herein to exposinga photoresist composition to radiation that is activating for thephotoresist indicates that the radiation is capable of forming a latentimage in the photoresist such as by causing a reaction of thephotoactive component (e.g. producing photoacid from the photoacidgenerator compound).

As discussed above, photoresist compositions are preferablyphotoactivated by a short exposure wavelength, particularly a sub-400nm, sub-300 and sub-200 nm exposure wavelength, with I-line (365 nm),248 nm and 193 nm being particularly preferred exposure wavelengths aswell as EUV and 157 nm.

Following exposure, the film layer of the composition is preferablybaked at temperatures ranging from about 70° C. to about 160° C.Thereafter, the film is developed, preferably by treatment with anaqueous based developer such as quaternary ammonium hydroxide solutionssuch as a tetra-alkyl ammonium hydroxide solution; various aminesolutions preferably a 0.26 N tetramethylammonium hydroxide, such asethyl amine, n-propyl amine, diethyl amine, di-n-propyl amine, triethylamine, or methyldiethyl amine; alcohol amines such as diethanol amine ortriethanol amine; cyclic amines such as pyrrole, pyridine, etc. Ingeneral, development is in accordance with procedures recognized in theart.

Following development of the photoresist coating over the substrate, thedeveloped substrate may be selectively processed on those areas bared ofresist, for example by chemically etching or plating substrate areasbared of resist in accordance with procedures known in the art. For themanufacture of microelectronic substrates, e.g., the manufacture ofsilicon dioxide wafers, suitable etchants include a gas etchant, e.g. ahalogen plasma etchant such as a chlorine or fluorine-based etchant sucha Cl₂ or CF₄/CHF₃ etchant applied as a plasma stream. After suchprocessing, resist may be removed from the processed substrate usingknown stripping procedures.

All documents mentioned herein are incorporated herein by reference. Thefollowing non-limiting examples are illustrative of the invention. Alldocuments mentioned herein are incorporated by reference in theirentirety.

EXAMPLE 1 Carboxy Resin Preparation

A carboxy terpolymer resin having the following structure was preparedas described

A. Monomer and initiator mixture: weigh 7.00 g ofCH₃(CH═CH)C(═O)OCH(CH₃)CH₂C(CH₃)₂OH (the first monomer), 2.80 g of(CH₂═CH)C(═O)OC(CH(CH₃))₂C(CH₃)₃ (the second monomer) and 2.0 g ofacetic anhydride (the third monomer), 0.42 g of Trignox-23 (initiator)and 17.0 g PGMEA (solvent) into a feeding vial.B. Reactor: 30 g of PGMEA in a reactor and maintain at 85° C.C. Feed A into B: A is fed into B with a constant feeding rate in 120minutes.D. Holding temperature: after feeding A into B, the temperature of thereactor is maintained at 85° C. for additional two hrs, then allow thereactor temp to cool down naturally to room temperature.

The carboxy resin from the reactor can be used in a photoresistcomposition without further purification.

EXAMPLE 2 Additional Carboxy Resin Preparation

By procedures similar to those of Example 1, the following carboxy resinis prepared:

EXAMPLE 3 Hetero-Substituted Carbocyclic Aryl Resin Preparation

A hydroxy naphthyl terpolymer resin having the following structure wasprepared as described below:

1. Reactor: Add 20 g of propylene propylene glycol methyl ether acetate(PGMEA) to a 100 ml flask with a magnetic stir bar, and place the flaskin a bath at 85° C. with stirring and with reflux condenser. Purge thereactor with dry nitrogen.2. Monomer/initiator Solution: Weigh 6.5 g of4,4,4-trifluoro-3-hydroxy-1-methyl-3-(trifluoromethyl)butyl-2-methacrylate,and 1.0 g of hydroxy vinyl naphthalene, and 2.5 g of 2,3,3-trimethylacrylate into a suitable vial. Then add to the vial 10.0 g of PGMEA.Shake the vial to dissolve all the monomers, and then place the vial ina ice bath to cool the monomer solution to 0° C. Then add 0.3 g oftert-butyl peroxyneodecanoate (initiator of Triganox 23, from NouryChemicals) to the monomer vial and shake the vial to dissolve theinitiator. Place the monomer/initiator solution in the ice bath.3. Polymerization: Feed the monomer/initiator solution into the reactorin 90 minutes with a suitable feeding pump while maintaining themonomer/initiator vial in the ice bath. After feeding themonomer/initiator solution, the reactor is kept at 85° C. for additional3 hours with stirring. The reactor was then allowed to cool to room tempnaturally. The concentration of the polymer obtained in the reactor is23 to 25% in general, Mw: 10,000 to 12,000.

EXAMPLE 4 Sulfonamide Resin Preparation

A sulfonamide copolymer resin having the following structure wasprepared as described below:

A. Monomer and initiator mixture: weigh 7.00 g ofCH₃(CH═CH)C(═O)OCH(CH₃)CH₂C(CH₃)₂OH (the first monomer), 2.80 g of(CH₂═CH)C(═O)OC(CH₂)₂NHSO₂CF₃ (the second monomer) 0.42 g of Trignox-23(initiator) and 17.0 g PGMEA (solvent) into a feeding vial.B. Reactor: 30 g of PGMEA in a reactor and maintain at 85° C.C. Feed A into B: A is fed into B with a constant feeding rate in 120minutes.D. Holding temperature: after feeding A into B, the temperature of thereactor is maintained at 85° C. for additional two hrs, then allow thereactor temp to cool down naturally to room temperature.

The sulfonamide resin from the reactor can be used in a photoresistcomposition without further purification.

EXAMPLE 5 Photoresist Preparation and Processing

A photoresist composition is prepared by admixing the followingmaterials in the specified amounts:

1. Resin component: Terpolymer of (2-methyl-2-adamantylmethacrylate/beta-hydroxy-gamma-butyrolactonemethacrylate/cyano-norbornyl methacrylate in an amount of 6.79 weight %based on total weight of the photoresist composition;2. Photoacid generator compound: T-butyl phenyl tetramethylene sulfoniumperfluorobutanesulfonate in an amount of 0.284 weight % based on totalweight of the photoresist composition;3. Base additive: N-Alkyl Caprolactam in an amount of 0.017 weight %based on total weight of the photoresist composition;4. Surfactant: R08 (fluorine-containing surfactant, available fromDainippon Ink & Chemicals, Inc.) in an amount of 0.0071 weight % basedon total weight of the photoresist composition5. Substantially non-mixable additive: Polymer of Example 1 prepared asdescribed in Example 1 above and in an amount of 0.213 weight % based ontotal weight of the photoresist composition.6. Solvent component: propylene glycol monomethyl ether acetate toprovide about a 90 percent fluid composition.

This photoresist composition containing is spin-coated onto siliconwafers, dried on vacuum hotplate to remove soft-plate and then exposedin an immersion lithography process with aqueous immersion fluiddirectly contacting the dried photoresist layers. In that immersionsystem, the photoresist layers is exposed to patterned 193 nm radiationat a dose of 24.1 mJ/cm² for the control photoresist layers and 23.4mJ/cm².

The photoresist layers is then post-exposed baked (such as at about 120°C.) and developed with 0.26N alkaline aqueous developer solution.

To evaluate leaching of resist components after the post-exposure bakeand before development, the immersion fluid is evaluated for thephotoacid in the resist and its photo-degradation byproducts by LC/massspectroscopy (60 second leaching time tested).

1. A method for processing a photoresist composition, comprising: (a)applying on a substrate a photoresist composition comprising: (i) one ormore resins that comprise photoacid-labile groups, (ii) a photoactivecomponent, and (iii) one or more materials that comprise photoacidlabile groups and that are distinct from the one or more resins; whereinthe deprotection activation energy of photoacid-labile groups of the oneor more materials is about the same as or lower than the deprotectionactivation energy of photoacid-labile groups of the one or more resins;and (b) immersion exposing the photoresist layer to radiation activatingfor the photoresist composition.
 2. The method of claim 1 wherein theone or more materials are substantially non-mixable with the one or moreresins.
 3. The method of claim 1 wherein the deprotection activationenergy of photoacid-labile groups of the one or more materials is lowerthan the deprotection activation energy of photoacid-labile groups ofthe one or more resins.
 4. The method of claim 1 wherein the one or moreresins comprise photoacid-labile groups that are ester groups and doesnot comprise acetal photoacid-labile groups and the one or morematerials comprise photoacid-labile groups that are acetal groups. 5.The method of claim 1 wherein the one or more materials comprisephotoacid-labile groups that comprise more carbon chain branching thanthe photoacid-labile groups of the one or more resins.
 6. A method forprocessing a photoresist composition, comprising: (a) applying on asubstrate a photoresist composition comprising: (i) one or more resins,(ii) a photoactive component, and (iii) one or more materials thatcomprise a sufficient amount of acidic groups to provide a dark fielddissolution rate of at least one angstrom per second; and (b) immersionexposing the photoresist layer to radiation activating for thephotoresist composition.
 7. The method of claim 6 wherein the one ormore materials comprise one or more acidic groups selected fromfluorinated alcohols, sulfonamide, hetero-substituted carbocyclic aryl,and carboxy.
 8. The method of claim 6 wherein the one or more materialscomprise one or more acidic groups selected from (CF₃)₂C(OH)—,hydroxynaphthyl or COOH.
 9. The method of claim 6 wherein one or morematerials that comprise a sufficient amount of acidic groups to providea dark field dissolution rate of at least two, three, four or fiveangstroms per second.
 10. The method of claim 6 wherein the one or morematerials are substantially non-mixable with the one or more resins. 11.The method of claim 1 wherein the one or more materials are resins. 12.A coated substrate system comprising: a substrate having thereon: acoating layer of a photoresist composition, the photoresist compositioncomprising: (i) one or more resins that comprise photoacid-labilegroups, (ii) a photoactive component, and (iii) one or more materialsthat comprise photoacid labile groups and that are distinct from the oneor more resins; wherein the deprotection activation energy ofphotoacid-labile groups of the one or more materials is about the sameas or lower than the deprotection activation energy of photoacid-labilegroups of the one or more resins.
 13. A coated substrate systemcomprising: a substrate having thereon: a coating layer of a photoresistcomposition, the photoresist composition comprising: (i) one or moreresins, (ii) a photoactive component, and (iii) one or more materialsthat comprise a sufficient amount of acidic groups to provide a darkfield dissolution rate of at least one angstrom per second.
 14. Thesystem of claim 12 wherein an immersion lithography fluid contacts thetop surface of the photoresist coating layer.
 15. The system of claim 13further comprising an immersion photolithography exposure tool.
 16. Aphotoresist composition comprising: (i) one or more resins that comprisephotoacid-labile groups, (ii) a photoactive component, and (iii) one ormore materials that comprise photoacid labile groups and that aredistinct from the one or more resins; wherein the deprotectionactivation energy of photoacid-labile groups of the one or morematerials is about the same as or lower than the deprotection activationenergy of photoacid-labile groups of the one or more resins.
 17. Aphotoresist composition comprising: (i) one or more resins, (ii) aphotoactive component, and (iii) one or more materials that comprise asufficient amount of acidic groups to provide a dark field dissolutionrate of at least one angstrom per second.